Poor service and lack of regard for their clients

Poor service and lack of accountability for a mistake that they did on my account. I put in a tracking device on my car for a certain amount and they were deducting more than what we had agreed on until i cancelled and stopped the debit at the bank. They called me countless times whereby I explained this and they would say they understand that it is their fault and that they would revert back to me. This happened over months and they would fail to return those calls that charts a way forward. This morning i receive an email that says they have blacklisted me.

This is poor service and lack of regard for clients.